BrainStuff Classics: When We Lose Weight, Where Does It Go?

both within and without our control. Our genes might be a little tighter or a little looser. Our question of the day is when we lose weight, where does that lost weight go? The short answer is that our bodies convert molecules in fat cells two usable forms of energy, thus shrinking the cells. But getting this to happen isn't just about sweating to the oldies or however you prefer.

at maximum speeds. In short, more work means more energy is needed. The body uses some of the calories we ingest to digest that very food. Once the food is broken down into its respective parts of carbohydrates, fats, and proteins, it either uses the remaining energy or converts to fat for storage in fat cells. And as doctor who fans know, fat cells live in adipose tissue, which basically acts like

an internal gas station storing away fuel reserves. To lose weight, you must burn more calories or of energy than you consume to start using up that fuel reserve. Essentially, if you're not ingesting enough calories to fuel your additional work, your body must pull from fat stores. According to the law of conservation of mass, matter is neither created nor destroyed,

but it may alter its form through chemical reaction. Essentially, that tells us that while we lose mass in our bodies by burning up fat, it doesn't just disappear, it simply changes form. When we eat, the glucose and other sugars harnessed from carbohydrates are the first things our bodies

use as fuel stores. The liver stores the glucose in the form of glycogen and releases it into the bloodstream as necessary to keep our bodies trucking a long Think of your blood stream as an interconnected conveyor belt that takes necessary nutrients to the body parts that need them. Once that glucose runs out, fat takes over. Harnessing energy by burning fat is referred to as catosis. It works

like this. Hormones regulating our blood sugar levels activate an enzyme in the blood vessels of fat tissue called liepace. Liepace ignites fat cells to release macromolecules called triglycerides, which are what makes fat cells fat. Sutorides are made up of glycerool and three fatty acid chains. When they receive the signal from lipase to exit the fat cells, the triglyrides break up into their respective components and enter the

bloodstream for use. The liver snatches up the glycrool to break it down for energy, and some of the fatty acids move to the muscles that can farm them for energy as well. The action of breaking down triglycerides into usable energy is called like polysis. Once the components of the glycerol and fatty acids are inside are muscle or liver cells, organelles called mitochondria shuffle and reshuffle those compounds to harness their potential energy, sort of like a furnace

burns wood. The mitochondria break down and recombine those components of our fat cells and produce heat, water, carbon dioxide, and adenysine. Triphosphate or ATP. ATP hauls potential energy in its molecular bonds for use. When we exercise, like intercellular carb loading, the water exits our bodies as sweat and urine, and we exhale the carbon dioxide. Now that the body has really leaved fat cells of some glycerool and fatty acids, the cells get smaller and so sell by cell, our

body shape changes. Today's episode is based on the article when we Lose weight, Where does the lost weight Go? On How Stuffworks dot Com, written by Kristin Conger. To hear more from Kristin, check.